This invention concerns novel heterocyclic carboxamide derivatives and, more particularly, novel benzoic acids (and related tetrazoles and acylsulphonamides) derived from benzoheterocyclylcarboxamides, which antagonise the pharmacological actions of one or more of the arachidonic acid metabolites known as leukotrienes (hereinafter referred to as "leukotriene antagonist properties"). The novel derivatives are useful whenever such antagonism is desired. Thus, such compounds may be of value in the treatment of those diseases in which leukotrienes are implicated, for example in the treatment of allergic disorders, such as, for example, asthma, or of inflammatory diseases, or of endotoxic or traumatic shock conditions. The invention also provides pharmaceutical compositions containing the novel derivatives for use in such treatments, and processes and intermediates for the manufacture of the novel derivatives.
In European patent application, publication number 0 166 591 A2 there are described indole-2-alkanoic acids and their use as prostaglandin antagonists and as inhibitors of the synthesis of leukotrienes. We have now discovered a series of benzoheterocyclic derivatives which have a carboxamidic substituent in the benzenoid ring and which unexpectedly possess the property of antagonising one or more of the arachidonic acid metabolites known as leukotrienes and this is the basis for our invention.